Tranexamic acid formulations

ABSTRACT

Disclosed are modified release oral tranexamic acid formulations and methods of treatment therewith.

This application is a continuation of U.S. patent application Ser. No. 11/072,194 filed Mar. 4, 2005 which claims the benefit of U.S. Provisional Application No. 60/550,113, filed Mar. 4, 2004, and U.S. Provisional Application No. 60/592,885, filed Jul. 30, 2004, the disclosures of which are both hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

The invention is directed to modified release oral tranexamic acid formulations that preferably minimize or eliminate undesirable side effects and methods of treatment with these formulations.

BACKGROUND OF THE INVENTION

Tranexamic acid (trans-4-(aminomethyl)cyclohexanecarboxylic acid, Cyklokapron® (Pfizer) is an antifibrinolytic agent. That is, it helps to prevent lysis or dissolution of a fibrin clot which forms in the normal physiologic process of hemostasis. Its mechanism of action is as a competitive inhibitor of plasminogen activation, and as a noncompetitive inhibitor of plasmin; both plasminogen and plasmin are activators of fibrinolysis and active clot-lysing agents. Tranexamic acid thus helps to stabilize fibrin clots, which in turn maintains coagulation and helps to control bleeding.

Tranexamic acid is used to control excess bleeding, for example, excess bleeding that occurs during dental procedures in hemophiliacs and for heavy bleeding during menstruation (menorrhagia). Women suffering from menorrhagia are typically treated orally with 500 mg tranexamic acid tablets administered three or four times daily with a total daily dose ranging from 3 grams/day (two tablets every eight hours) to 6 grams/day (three tablets every six hours). However, this treatment may cause adverse gastrointestinal reactions, including nausea, vomiting, diarrhea, and cramping, etc. These gastrointestinal side effects are due to the quantity of tranexamic acid and/or rapid rate of release of tranexamic acid into the stomach with each dose, as well as the large quantity of excipients used in the tablet formulation that are introduced into the stomach. Such side effects, in addition to the cramping, bloating, pain, and other symptoms that may accompany menses, are undesirable, and a formulation of tranexamic acid is needed which will reduce or eliminate these side effects.

SUMMARY OF THE INVENTION

Formulations of tranexamic acid which minimize or eliminate the undesirable gastrointestinal side effects in patients on oral tranexamic acid therapy, e.g. women treated for menorrhagia (heavy menstrual bleeding) are disclosed. The present invention is directed in part to a modified release formulation, formulated so that the release of tranexamic acid thereof from the dosage form occurs in a designed fashion to prevent a bolus of tranexamic acid being introduced into the stomach and available for dissolution in the gastric contents. Such modified release formulations reduce the concentration of tranexamic acid dissolved in the stomach contents such as e.g., preventing a large bolus of tranexamic acid being introduced in the stomach. The beneficial effect of this reduced tranexamic acid concentration is to lower the amount of tranexamic acid in the gastric contents so that there are fewer adverse effects with tranexamic acid therapy. This reduction in adverse effects preferably results in improved patient compliance with therapy, because preferably patients will not intentionally miss taking a dose to avoid these adverse side effects. Physicians will also preferably be more likely to initiate and maintain tranexamic acid treatment for their patients because of the reduced patient complaints.

It is an object of the invention to provide an oral dosage form comprising tranexamic acid which is suitable for administration on a two or three times a day basis to humans.

It is a further object of the invention to provide a modified release oral dosage form comprising tranexamic acid and a modified release material which provides for the modified release of the tranexamic acid and is suitable for administration on a two or three times a day basis.

It is a further object of certain embodiments of the present invention to provide a modified release oral dosage form comprising tranexamic acid and a modified release material which minimizes or eliminates the undesirable gastrointestinal side effects in patients on oral tranexamic acid therapy while maintaining or improving the therapeutic effect of tranexamic acid.

It is a further object of certain embodiments of the present invention to provide a method of treating a patient suffering from heavy menstrual bleeding (menorrhagia) by orally administering to the patient one or more dosage forms comprising tranexamic acid and a modified release material which provide(s) for therapeutically effective levels of tranexamic acid suitable for two or three times a day administration.

The above advantages and objects and others can be achieved by virtue of the present invention which is directed in part to a modified release oral dosage form comprising tranexamic acid or a pharmaceutically acceptable salt thereof and a modified release material which provides for the modified release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dosage form is suitable for administration on a two or three times a day basis; said dosage form providing an in-vitro dissolution release rate of the tranexamic acid or pharmaceutically acceptable salt thereof, when measured by a USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C., of less than about 70% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 45 minutes and about 100% by weight of said tranexamic acid or pharmaceutically acceptable salt thereof released by about 120 minutes.

In certain embodiments, the present invention is directed to a method of treating a patient in need of tranexamic acid or pharmaceutically acceptable salt thereof therapy comprising administering to the patient about 1300 mg of tranexamic acid or pharmaceutically acceptable salt thereof in at least one oral dosage form comprising said tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which provides a mean maximum plasma concentration (C_(max)) of tranexamic acid of from about 5 to about 17.5 mcg/ml, preferably from about 6.5 to about 15 mcg/ml, more preferably from about 9 to about 14.5 mcg/ml after single dose oral administration to humans.

In certain embodiments, the invention is further directed to a method of treating a patient in need of tranexamic acid or pharmaceutically acceptable salt thereof therapy comprising administering to the patient about 1300 mg of tranexamic acid or pharmaceutically acceptable salt thereof in at least one oral dosage form comprising said tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which provides a mean maximum plasma concentration (C_(max)) of tranexamic acid of from about 5 to about 25 mcg/ml, preferably from about 10 to about 20 mcg/ml, more preferably from about 12.5 to about 17.5 mcg/ml, most preferably about 15 to about 17 mcg/ml after steady state oral administration to humans.

In certain embodiments, the modified release oral dosage form of the present invention provides a mean T_(max) of tranexamic acid at from about 1 to about 5.5 hours, preferably at from about 2 to about 4 hours, more preferably at from about 2 to about 3.5 hours after oral administration of the dosage form to humans.

In certain embodiments, the invention is further directed to a modified release oral dosage form comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which provides for the modified release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dosage form is suitable for administration on a two or three times a day basis and the dosage form provides a dissolution release rate in-vitro of the tranexamic acid or pharmaceutically acceptable salt thereof when measured by the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. of less than about 40% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 15 minutes, less than about 70% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 45 minutes, and not less than 50% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 90 minutes.

In certain embodiments, the invention is further directed to a modified release oral dosage form comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which provides for the modified release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dosage form is suitable for administration on a two or three times a day basis and the dosage form provides a dissolution release rate in-vitro of the tranexamic acid or pharmaceutically acceptable salt thereof when measured by the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. of about 0% to about 40% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 15 minutes, from about 20% to about 60% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 30 minutes, from about 40% to about 65% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 45 minutes, from about 50% to about 90% by weight tranexamic acid or pharmaceutically acceptable salt thereof release at about 60 minutes, and not less than 60% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 90 minutes.

In certain embodiments, the invention is further directed to a modified release oral dosage form comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material, which provides for a bioavailability of tranexamic acid of greater than 40%, from about 41% to about 60%, preferably from about 42% to about 50%, more preferably about 45% after oral administration to humans

In certain embodiments, the present invention is further directed to a modified release oral dosage form comprising from about 585 to about 715 mg of tranexamic acid or pharmaceutically acceptable salt thereof, preferably about 650 mg of tranexamic acid or pharmaceutically acceptable salt thereof, and a modified release material which provides for the modified release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dosage form is suitable for administration on a two or three times a day basis.

In certain embodiments, the present invention is directed to a modified release oral dosage form comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which provides for the modified release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dosage form is suitable for administration on a two or three times a day basis, the dosage form providing a reduction of at least one side effect selected from the group consisting of headache, nausea, vomiting, diarrhea, constipation, cramping, bloating, and combinations thereof, as compared to an equivalent amount of tranexamic acid or pharmaceutically acceptable salt thereof in an immediate release oral dosage form when administered across a patient population.

In certain embodiments, the present invention is directed to a modified release oral dosage form comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release excipient, said dosage form providing for the release of the tranexamic acid or pharmaceutically acceptable salt thereof which is slower than an immediate release oral dosage form and faster than a controlled release oral dosage form, such that the modified release oral dosage form is suitable for administration two or three times a day.

In certain embodiments, the invention is further directed to a modified release oral dosage form comprising about 650 mg of tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material, the dosage form being suitable for oral administration on a three times a day basis, and the dosage form providing a mean maximum plasma concentration (C_(max)) of tranexamic acid of from about 5 to about 17.5 mcg/ml, preferably from about 6.5 to about 15 mcg/ml, more preferably from about 9 to about 14.5 mcg/ml per 1300 mg tranexamic acid after single dose oral administration to humans.

In certain embodiments, the invention is further directed to a modified release oral dosage form comprising about 650 mg of tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material, the dosage form being suitable for oral administration on a twice a day basis, and the dosage form providing a mean maximum plasma concentration (C_(max)) of tranexamic acid of from about 5 to about 40 mcg/ml, preferably from about 10 to about 30 mcg/ml per 1950 mg tranexamic acid after single dose oral administration to humans.

In certain embodiments, the invention is further directed to a modified release oral dosage form comprising about 650 mg of tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material, the dosage form being suitable for oral administration on a three times a day basis, and the dosage form providing a mean plasma concentration of tranexamic acid of from about 5 to about 25 mcg/ml, preferably from about 7.5 to about 15 mcg/ml, more preferably from about 8 to about 10 mcg/ml, most preferably about 9 mcg/ml per 1300 mg tranexamic acid after steady state oral administration to humans.

In certain embodiments, the invention is further directed to a modified release oral dosage form comprising about 650 mg of tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material, the dosage form being suitable for administration on a three times a day basis, and the dosage form providing a mean maximum plasma concentration (C_(max)) of tranexamic acid of from about 5 to about 25 mcg/ml, preferably from about 10 to about 20 mcg/ml, more preferably from about 12.5 to about 17.5 mcg/ml, most preferably about 15 to about 17 mcg/ml per 1300 mg tranexamic acid after steady state oral administration to humans.

In certain embodiments, the invention is further directed to a modified release oral dosage form comprising about 650 mg of tranexamic acid or pharmaceutically acceptable salt thereof and an modified release material, the dosage form being suitable for administration on a three times a day basis, and the dosage form providing a mean plasma trough concentration of tranexamic acid or pharmaceutically acceptable salt thereof of from about 2 to about 10 mcg/ml, preferably from about 3 to about 7.5 mcg/ml, more preferably about 4 to about 7 mcg/ml, most preferably about 5 to about 6 mcg/ml per 1300 mg tranexamic acid or after steady state oral administration to humans.

In certain embodiments, the invention is further directed to a method of treating a patient with a therapeutically effective amount of tranexamic acid or pharmaceutically acceptable salt thereof comprising administering to the patient two dosage forms of the present invention, each dosage form comprising from about 585 mg to about 715 mg of tranexamic acid or pharmaceutically acceptable salt thereof, preferably about 650 mg tranexamic acid or pharmaceutically acceptable salt thereof, and a modified release material such that the dosage form is suitable for oral administration on a three times a day basis.

In certain embodiments, the invention is further directed to a method of treating a patient with a therapeutically effective amount of tranexamic acid or pharmaceutically acceptable salt thereof comprising administering to the patient three dosage forms of the present invention, each dosage form comprising from about 585 mg to about 715 mg, preferably about 650 mg tranexamic acid or pharmaceutically acceptable salt thereof, and a modified release material such that the dosage form is suitable for oral administration on a twice a day basis.

In certain embodiments, the invention is directed to a dose of tranexamic acid or pharmaceutically acceptable salt thereof comprising two unit dosage forms of a modified release formulation, each unit dosage form of said modified release formulation comprising from about 585 mg to about 715 mg, preferably about 650 mg of tranexamic acid or pharmaceutically acceptable salt thereof, and a modified release material which provides for the release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dose provides a therapeutic effect when administered three times a day.

In certain embodiments, the invention is directed to a dose of tranexamic acid comprising three unit dosage forms of a modified release formulation, each unit dosage form of said modified release formulation comprising from about 585 mg to about 715 mg, preferably about 650 mg of tranexamic acid or pharmaceutically acceptable salt thereof, and a modified release material which provides for the release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dose provides a therapeutic effect when administered twice a day.

In certain preferred embodiments, the invention is further directed to a modified release oral dosage form including tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which provides for the modified release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dosage form is suitable for administration on a two or three times a day basis and the dosage form provides a dissolution release rate in-vitro of the tranexamic acid or pharmaceutically acceptable salt thereof when measured by the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. of about 0% to about 40% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 15 minutes, from about 20% to about 60% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 30 minutes, from about 40% to about 80% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 45 minutes, from about 50% to about 95% by weight tranexamic acid or pharmaceutically acceptable salt thereof release at about 60 minutes, and not less than about 60% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 90 minutes.

In certain preferred embodiments, the invention is further directed to a modified release oral dosage form including tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which provides for the modified release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dosage form is suitable for administration on a two or three times a day basis and the dosage form provides a dissolution release rate in-vitro of the tranexamic acid or pharmaceutically acceptable salt thereof when measured by the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. of about 14% to about 22% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 15 minutes, from about 32% to about 50% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 30 minutes, from about 47% to about 71% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 45 minutes, from about 61% to about 92% by weight tranexamic acid or pharmaceutically acceptable salt thereof release at about 60 minutes, and from about 79% to about 100% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 90 minutes.

In certain embodiments, the invention is directed to a modified release oral dosage form comprising tranexamic acid or pharmaceutically acceptable salt thereof and an effective amount of a modified release excipient such that the dosage form releases from about 10% to about 25% by weight tranexamic acid or pharmaceutically acceptable salt thereof every 15 minutes when measured in vitro utilizing the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. In certain preferred embodiments, the dosage form releases about 18% to about 23% by weight tranexamic acid or pharmaceutically acceptable salt thereof every 15 minutes when measured in vitro utilizing the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. Most preferably, the dosage form releases about 100% of said tranexamic acid or pharmaceutically acceptable salt thereof within about 120 minutes when measured in vitro utilizing the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. In certain embodiments, the dosage form releases about 1% of said tranexamic acid or pharmaceutically acceptable salt thereof every minute when measured in vitro utilizing the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C.

In certain preferred embodiments, the modified release oral dosage form of the invention further provides a mean transit time of said tranexamic acid of 7.70±0.72 hours when administered across a patient population.

In certain preferred embodiments, the modified release oral dosage form of the invention further provides a mean absorption time of said tranexamic acid of 4.18±0.70 hours when administered across a patient population.

In certain further embodiments, the modified release oral dosage form of the present invention provides confidence intervals derived from ln-transformed pharmacokinetic kinetic parameters AUC_(0-t), AUC_(inf) and C_(max) for tranexamic acid in plasma which are within a 80-125% range of an immediate release formulation including an equivalent amount of tranexamic acid when administered across a patient population under fasted conditions.

In certain embodiments, the invention is further directed to a modified release oral dosage form comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which provides for the modified release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dosage form is suitable for administration on a two or three times a day basis and the dosage form provides less than about 20 percent incidence of headache as a side effect after single dose oral administration across a patient population.

In certain embodiments, the invention is further directed to a modified release oral dosage form comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which provides for the modified release of the tranexamic acid or pharmaceutically acceptable salt thereof from the dosage form such that the dosage form is suitable for administration on a two or three times a day basis and the dosage form provides less than about 10 percent incidence of nausea as a side effect when administered across a patient population, less than about 7 percent incidence of nausea when administered across a patient population, preferable less than about 5 percent incidence of nausea as a side effect when administered across a patient population, more preferably less than about 2 percent incidence of nausea as a side effect after single dose oral administration across a patient population.

In certain embodiments, the modified release oral dosage form of the present invention provides less CNS side effects (e.g., headache), less GI side effects (e.g., nausea), or combination thereof in comparison to an equivalent amount of tranexamic acid or pharmaceutically acceptable salt thereof in an immediate release formulation when administered across a patient population. Additionally or alternatively, in certain embodiments the dosage form provides less CNS side effects (e.g., headache), less GI side effects (e.g., nausea), or combination thereof in comparison to a therapeutically equivalent amount of tranexamic acid administered intravenously in five minutes or less across a patient population.

In certain embodiments, the modified release oral dosage form of the present invention provides for the reduction of at least one side effect as compared to an immediate release oral dosage form including an equivalent amount of tranexamic acid or pharmaceutically acceptable salt thereof, when the immediate release dosage form is administered across a same or different population of patients as said modified release dosage form, and wherein said immediate release dosage form releases all of said tranexamic acid or pharmaceutically acceptable salt thereof within about 45 minutes when measured in vitro utilizing the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. Such side effects can be for example, headache, nausea, vomiting, diarrhea, constipation, cramping, bloating, and combinations thereof

In certain embodiments, the modified release oral dosage form of the present invention provides a mean transit time of tranexamic acid which is at least about 20 minutes longer, preferably about 30 minutes longer, than an immediate release formulation including an equivalent amount of tranexamic acid when administered across a patient population.

In certain embodiments, the dosage form of the present invention provides a mean absorption time of tranexamic acid which is at least about 20 minutes longer, preferably about 30 minutes longer, than an immediate release formulation including an equivalent amount of tranexamic acid when administered across a patient population.

In certain preferred embodiments, the therapeutically effective dose of the tranexamic acid or pharmaceutically acceptable salt thereof is provided via the administration of two or more dosage units. For example, if the dosage unit comprises 650 mg of tranexamic acid or pharmaceutically acceptable salt thereof and the dose for administration is about 1300 mg then two dosage units would be administered to a patient in need of such treatment, or for example, when the dose for administration is 1950 mg, three dosage units would be administered.

In certain preferred embodiments, the invention is further directed to a method of treating a patient with one or more modified release oral dosage forms comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material, wherein the oral dosage form provides a therapeutically effective plasma level of tranexamic acid or pharmaceutically acceptable salt thereof in accordance with a three times a day (TID) dosing schedule, and the therapeutically effective dose administered comprises about 1300 mg of tranexamic acid or pharmaceutically acceptable salt thereof.

In certain preferred embodiments, the invention is further directed to a method of treating a patient with one or more modified release oral dosage forms comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material, wherein the oral dosage form provides a therapeutically effective plasma level of tranexamic acid or pharmaceutically acceptable salt thereof in accordance with a twice a day (BID) dosing schedule, and the therapeutically effective dose administered comprises about 1950 mg of tranexamic acid or pharmaceutically acceptable salt thereof.

In certain embodiments, the invention is directed to a method of providing a tranexamic acid plasma concentration within the range of about 5 mcg/mL to about 15 mcg/mL by administration of a modified release formulation of the present invention comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material on a three times a day basis to a patient in need of tranexamic acid or pharmaceutically acceptable salt thereof treatment.

In certain embodiments, the invention is further directed to a method of treating a human patient with heavy menstrual bleeding (e.g., menorrhagia) comprising administering about 1300 mg of tranexamic acid or pharmaceutically acceptable salt thereof on a three times a day basis to the human patient to provide a tranexamic acid or pharmaceutically acceptable salt thereof plasma concentration within the range of about 5 mcg/mL to about 15 mcg/mL after steady state oral administration to a human patient.

In certain embodiments, the invention is directed to a method of treating a patient suffering from menorrhagia, conization of the cervix, epistaxis, hyphema, hereditary angioneurotic edema, a patient with a blood coagulation disorder undergoing dental surgery, combinations thereof, and the like, by administering at least one dosage form of the present invention to the patient in need in tranexamic acid or pharmaceutically acceptable salt thereof therapy.

In certain embodiments, the invention is directed to a method of treating heavy menstrual bleeding with a therapeutically effective dose of at least one oral formulation of the present invention comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material wherein the menstrual blood loss per menstrual cycle is reduced by at least about 10 ml, preferably at least about 20 ml, more preferably at least about 40 ml. In a most preferred embodiment the menstrual blood loss per menstrual cycle is reduced by greater than or equal to about 50 ml.

In certain embodiments, the invention is directed to a method of treating heavy menstrual bleeding with a therapeutically effective dose of at least one oral formulation of the present invention comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which upon oral administration to a human female reduces the blood loss per menstrual cycle by about 35 ml to about 200 ml, preferably about 40 ml to about 175 ml, more preferably from about 50 ml to about 150 ml.

In certain embodiments, the invention is further directed to a method of treating heavy menstrual bleeding with a therapeutically effective dose of at least one oral formulation of the present invention comprising tranexamic acid or pharmaceutically acceptable salt thereof and a modified release material which upon oral administration to a human female reduces the blood loss per menstrual cycle by about 20% to 100%, preferably from about 20% to about 70%.

The menstrual blood loss can be measured by procedures known in the art. For example, in certain embodiments, the menstrual blood loss can be determined by a procedure described by (i) L. Hallbert, et al. in “Determination of Menstrual Blood Loss”, Scandinav. J. Clin. & Lab. Investigation, 244-248, 16, 1964, wherein the procedure is performed by extracting the menstrual blood from vaginal tampons and towels with a sodium hydroxide solution, converting heme chromogens to alkaline hematin, which is determined spectrophotometrically; or (ii) the menstrual blood loss can be determined by a procedure described by J. Newton, M. D., et al., in “A Rapid Method for Measuring Menstrual Blood Loss Using Automatic Extraction.”, Contraception, 269-282, September 1977, Vol. 16, No. 3, wherein the procedure is based upon the formation of alkaline haematin after the blood has been extracted from vaginal tampons and sanitary towels by an automatic Stomacher Lab-Blender. The disclosures of the aforementioned articles are hereby incorporated by reference in their entireties.

In certain embodiments, the modified release material may be incorporated in a coating applied onto e.g., a tablet comprising the tranexamic acid or pharmaceutically acceptable salt thereof, may be incorporated into a matrix with the tranexamic acid or pharmaceutically acceptable salt thereof, or a combination thereof. For example, in certain preferred embodiments, the modified release material is a controlled release material such as a gel-forming or hydratable polymer which is added to e.g., a matrix composition comprising the tranexamic acid or pharmaceutically acceptable salt thereof.

In certain embodiments, the tranexamic acid for use in the methods and formulations of the present invention is in the form of a pharmaceutically acceptable salt thereof. Such salt forms include for example and without limitation the sodium salt, potassium salt, calcium salt, magnesium salt and the like; as well as the hydrochloride, hydrobromide, sulfate, phosphate, formate, acetate, trifluoroacetate, maleate, tartrate, methanesulfonate, benzenesulfonate, p-toluenesulfonatemethanesulfonate salt forms, and the like. Preferably the active ingredient for use in accordance with the present invention is tranexamic acid.

An “immediate release oral dosage form” for purposes of the present invention is a dosage form which releases all of active ingredient (e.g., tranexamic acid) included therein within about 45 minutes when measured in vitro utilizing the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C.

A “modified release oral dosage form” for purposes of the present invention is an oral dosage form which releases the active ingredient (e.g., tranexamic acid) included therein in a manner that is slower than an immediate release oral dosage form and faster than a controlled release oral dosage form, when the dosage forms include the same amount of active as the modified release oral dosage form. One definition of the terms “slower” and “faster” as used in this application is that they are meant to represent a statistically significant difference at each measured 15 minute interval after the start of in-vitro dissolution. In certain preferred embodiments, the modified release oral dosage form of the present invention provides an in-vitro dissolution release rate of tranexamic acid or pharmaceutically acceptable salt thereof, when measured by a USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C., of less than about 70% by weight tranexamic acid or pharmaceutically acceptable salt thereof released at about 45 minutes and about 100% by weight of said tranexamic acid or pharmaceutically acceptable salt thereof released by about 120 minutes.

A “controlled release oral dosage form” for purposes of the present invention is a dosage form which releases all of the active ingredient (e.g., tranexamic acid) included therein after about 4 hours or more when measured in vitro utilizing the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C.

The term “C_(max)” unless otherwise indicated is meant for purposes of the present invention to mean the maximum plasma concentration of a medicament achieved after single dose administration of a dosage form, or the maximum plasma concentration of a medicament achieved over a dosing interval from multiple-doses at steady-state in accordance with the present invention.

The term “T_(max)” is meant for purposes of the present invention to mean the elapsed time from administration of a dosage form to the time the C_(max) of the medicament is achieved.

The term “steady state” means that the amount of the drug reaching the system is approximately the same as the amount of the drug leaving the system. Thus, at “steady-state”, the patient's body eliminates the drug at approximately the same rate that the drug becomes available to the patient's system through absorption into the blood stream.

The term “mean” for purposes of the present invention, when used to define a pharmacokinetic value (e.g., T_(max)), unless specified otherwise, represents the arithmetic mean value measured across a patient or subject population.

The term “three times a day (TID) basis” for purposes of the present invention, means that the dosage regimen is to be administered three times a day, preferably on a schedule of every 8 hours.

The term “mean transit time” is understood by those skilled in the art and means the time-point where 63.2% of the total AUC is attained after oral administration, or 63.2% of the IV dose is eliminated, as described in Applied Pharmacokinetics, Principles of Therapeutic Drug Monitoring, Second Edition (1986), edited by William E. Evans, et al., the disclosure of which is hereby incorporated by reference in its entirety.

The term “mean absorption time” is understood by those skilled in the art and means a quantitative parameter which summarizes how long, on average, the drug molecule remains unabsorbed, i.e. persists in its dosage form and in the gastrointestinal tract, also as described in Applied Pharmacokinetics. Principles of Therapeutic Drug Monitoring, Second Edition (1986), edited by William E. Evans, et al. Unlike the absorption rate constants (ka) which can be skewed, the mean absorption time is not affected by incomplete release of drug from its dosage form, irregular absorption, lag-time, mixed zero-order dissolution rates, changing GI motility, GI blood flow, first-pass effect, etc.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts concentration-time profiles for simulated administration of the 1.3 g tranexamic acid modified release formulation of Example 1 at a Q8H (every 8 hours) dosing schedule of 6:00 AM, 2:00 PM, 10:00 PM comparing it with 1 g administered Q8 H.

FIG. 2 depicts concentration-time profiles for simulated administration of the 1.3 g tranexamic acid modified release formulation of Example 1 at a TID (three times a day) dosing schedule of 8:00 AM, 2:00 PM, 8:00 PM comparing it with 1 g administered TID.

FIG. 3 depicts mean plasma concentration-time profiles on a semi-log scale over 36 hours for the study of Example 4.

FIG. 4 depicts mean plasma concentration-time profiles on a linear scale over 36 hours for the study of Example 4.

DETAILED DESCRIPTION

The dosage regimen typically listed for tranexamic acid in HMB (Heavy Menstrual Bleeding) therapy is 1-1.5 g per dose administered three-four times a day at the onset of copious menstrual bleeding and continued for the first 3-5 days of the menstrual cycle. However, the most frequently reported dosage regimen of tranexamic acid is an immediate release oral formulation in which 1 g tranexamic acid is administered four times a day (4 g per day) for HMB therapy outside of the US. Knowledge of this common regimen is supported by a careful review of the randomized controlled trials published in the medical literature, product labeling from other countries' regulatory authorities having the product approved for HMB therapy, utilization data from Sweden (Rybo 1991), correspondence and interviews with non-US clinicians having experience with the product. That regimen is currently the dosage being studied by the US Center for Disease Control (CDC) in women with HMB associated with bleeding disorders.

The absolute bioavailability of tranexamic acid observed when administering the European commercial formulation (Cyklokapron, Kabi AB, Sweden Batch 90288; assay 499 mgm/tablet) to male subjects is approximately 35% and its elimination correlates with renal creatinine clearance. Peak serum tranexamic acid concentrations occur approximately 3 hours after the oral administration of a European immediate-release tablet formulation (>85% dissolved at 15 minutes) (Pilbrant, et al., Eur. J. Clin. Pharmacol, (1981)-20:65-72). By comparison, the in vivo absorption profile observed with the European immediate-release formulation is slow and very gradual over 3 hours. Specifically, tranexamic acid serum concentrations are 9, 41, 73, 88 percent (with food), and 22, 63, 85, and 98 percent (fasting) of maximal absorption at 0.5, 1, 1.5 and 2 hours after a 2 g oral dose, respectively. Although not wishing to be held to any specific theory, it is presently hypothesized that tranexamic acid oral absorption appears to be controlled by a non-dissolution rate limited process, i.e. the rate and extent of oral absorption is a function of a transmembrane passage-limited process, in order to explain the disparity between the time of product dissolution and relatively prolonged tmax (time to achieve the peak serum concentration).

Preferably, the goal of the formulation, dose strength and dosage regimen of the invention, is to provide HMB therapy which achieves from about 20% to 100% reduction in menstrual blood loss per menstrual cycle. In accordance with certain embodiments of the present invention, the preferred tranexamic acid dose of 1.3 g every 8 hours is predicted to provide an average serum tranexamic acid concentration comparable to that produced by a 1 g every 6 hour regimen (i.e. 12.4 mcg/mL), with associated peaks and troughs falling approximately within the therapeutic antifibrinolytic range (5-15 mcg/mL; Cyklokapron NDA 19-280). In certain embodiments, a two-compartment oral absorption and elimination simulation model coupled with pharmacokinetic data (Pilbrant, et al., Eur. J. Clin. Pharmacol, (1981)-20:65-72), and modified-release tablet dissolution performance information were used to determine the preferred lead dosage regimen.

In immediate release formulations the entire dose and the soluble components in the dosage form dissolve in gastrointestinal fluid and present a high concentration of solutes for absorption. The most frequently reported adverse effects are primarily confined to the proximal gastrointestinal tract (nausea and vomiting). These adverse symptoms appear to be related to the drug load presented to the gastric mucosa, since this effect can be minimized by reducing the immediate-release oral formulation dose or administering the product slowly by the intravenous route. In certain embodiments, a lower incidence of proximal gastrointestinal adverse effects is obtained with the preferred oral modified release formulation (e.g., dosed 1.3 g every 8 hours) of the invention, e.g., because of the modified release properties of the drug product formulation.

In certain embodiments, the oral dosage form of the present invention provides for an increased bioavailability as compared to immediate release oral dosage forms currently available (e.g., Cyclokapron). In certain preferred embodiments the increased bioavailability allows therapeutic plasma levels of tranexamic acid to be reached with a lower dose of drug. Preferably, the increased bioavailability also decreases the amount of tranexamic acid that remains unabsorbed in the gastrointestinal which leads to decreased incidence of side effects that are typically associated with formulations that provide higher levels of unabsorbed tranexamic acid and prolonged exposure of the gastrointestinal tract to the higher tranexamic acid levels. Preferably the oral dosage form of the present invention provides for a bioavailability of tranexamic acid of greater than 40%, from about 41% to about 60%, preferably from about 42% to about 50%, more preferably about 45% after oral administration to humans.

The modified release oral formulations of tranexamic acid of the present invention provides a release of the drug which is slower than that of the immediate release 500 mg Cyklokapron product current marketed in Canada which provided a mean release rate of 100% by weight tranexamic acid released by about 15 minutes when measured utilizing USP 27 Apparatus Type II paddle method @ 50 RPM in 900 ml water at 37±0.5° C.

In certain embodiments, the modified release oral formulations may be described as providing a mean transit time through the proximal gastrointestinal mucosa which takes approximately one half hour longer than an immediate release formulation. In other preferred embodiments, the modified release formulations of the invention provide a rate of release of (dissolved) tranexamic acid from the dosage form in-vitro which is approximately 20, 40, 60, 80, and 100 percent of the total dose at 0.25, 0.5, 0.75, 1 and 1.5 hours, respectively. In certain preferred embodiments, such a release rate in-vitro demonstrates that the formulations of the present invention provide a relative reduction in the amount and rate of dissolved tranexamic acid presented to the proximal gastric mucosa to approximate 20, 40, 60, 80, and 100 percent of the total dose at 0.25, 0.5, 0.75, 1 and 1.5 hours, respectively, after oral administration.

In certain embodiments, the majority of tranexamic acid absorption appears to occur slowly distal to the stomach, and assuming linear pharmacokinetics, the modified release formulation produces an absorption profile which is comparable to that achieved with the currently available oral immediate release formulations used outside the U.S.

In accordance with the present invention a modified release tranexamic acid tablet for oral administration is disclosed. Preferably, the tablet contains at least one material (defined herein as any substance other than the active, i.e., tranexamic acid) which minimizes or eliminates the adverse gastrointestinal side effects in patients, for example, women dosed with oral tranexamic acid for treatment of menorrhagia.

The modified release oral dosage forms of tranexamic acid for purposes of the present invention include formulation ingredients and/or configurations which are typically utilized for formulations known in the art as extended, sustained and controlled release formulations, although modified to provide a desirable release rate in keeping with the teachings of the present invention. The modified release formulations preferably decrease the concentration of tranexamic acid and materials dissolved in the stomach fluids after dosing by controllably releasing tranexamic acid over a period of time, as opposed to immediate release formulations which release the entire dose of tranexamic acid all at once. The modified release formulations of the present invention thus minimize or prevent gastrointestinal reactions and side effects that occur when a dose of tranexamic acid is ingested and immediately reaches the stomach.

The modified release dosage forms of the present invention may be prepared as; tablets, capsules, granules, pellets, powders, dragees, troches, non-pariels, pills or encapsulated suspension, and may be packaged into capsules, sachets, etc. Such dosage forms may be prepared by any formulation technique where release of the active substance (tranexamic acid) from the dosage form is modified to occur at a slower rate than from an immediate release product. In these formulations, tranexamic acid release occurs in the stomach and/or intestine, but at a slower rate so that a bolus of dissolved drug does not reach the lining of the stomach and cause adverse effects, or adverse effects occur with a lower intensity or frequency because of the lower concentration of tranexamic acid. Hence, adverse effects are preferably reduced, minimized or eliminated.

Methods of preparing modified release formulations are found in Modified Release Drug Delivery Technology, Rathbone, Hadgraft, and Roberts, Eds., Drugs and the Pharmaceutical Sciences, Vol. 126, Marcel Dekker Inc., New York, 2003; Modern Pharmaceutics, Third Edition, Banker and Rhodes, Eds. Drugs and the Pharmaceutical Sciences, Vol. 72, Marcel Dekker Inc., New York, 1996; Sustained and Controlled Release Drug Delivery Systems, Robinson, Ed., Drugs and the Pharmaceutical Sciences, Vol. 6, Marcel Dekker Inc., NY 1978; Sustained Release Medications, Chemical Technology Review No. 177, Johnson, Ed., Noyes Data Corporation 1980; Controlled Drug Delivery, Fundamentals and Applications, Second Edition, Robinson and Lee, Eds., Marcel Dekker Inc., New York, 1987, and as described in U.S. Pat. No. 6,548,084, each of these references being expressly incorporated by reference herein in its entirety.

Preferably, a modified release form, makes tranexamic acid available over an extended period of time after ingestion. Modified release dosage forms coupled with the digestion process and the absorption process in the gastrointestinal tract cause a reduction in the amount of tranexamic acid in solution in the gastrointestinal tract compared to dosing tranexamic acid presented as a conventional dosage form (e.g., as a solution, or as an immediate release dosage form). The modified release formulation may be verified by in vitro dissolution testing and in vivo bioequivalence documentation, according to Food and Drug Administration standards, e.g., as set forth at www.fda.gov, 21 CFR §314, 320, and also at USP 23 NF 18 §711, 724. For example, an in vitro dissolution test such as USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. may be used to verify the release of the tranexamic acid from the dosage form.

Tranexamic acid modified release tablets may be formulated to provide a dose of tranexamic acid, typically about 500 mg to about 2 grams from one to two tablets, within about the first one to two hours after the tablet is ingested. Thus, tranexamic acid release occurs at a designed rate over a period e.g., about 60 minutes to about 120 minutes. The rate of tranexamic acid release over this period of time is designed to provide a reduced concentration of tranexamic acid in the stomach while allowing the absorption of tranexamic acid to occur throughout the gastrointestinal tract. Absorption of tranexamic acid typically begins as soon as tranexamic acid is released from the dosage form and is dissolved in the gastrointestinal fluids contacting the membranes which line the gastrointestinal tract. The rate of release of tranexamic acid from the dosage form and the absorption of drug by the gastrointestinal mucosa help to maintain low concentrations of drug in the gastrointestinal fluids. The lowered concentrations preferably result in lower intensity, frequency, and/or severity of gastrointestinal adverse side effects. The designed rate of release of tranexamic acid from the dosage form in the stomach and the upper small intestine, the natural emptying of gastric juice containing any dissolved tranexamic acid from the stomach, and the absorption of tranexamic acid from a larger segment of the gastrointestinal tract (i.e., both the stomach and the small intestine, rather than the stomach only or the lower portion of the small intestine if any modified release dosage form with a longer release time was used), preferably results in reduced levels of dissolved tranexamic acid in the region of the gastrointestinal tract proximal or distal to the dosage form. Reduced concentrations of tranexamic acid along the gastrointestinal tract preferably provide a reduction in adverse gastrointestinal effects associated with oral tranexamic acid therapy.

As used herein, alleviation of adverse effects using these formulations indicates any relief in one or more symptoms, such as decrease in incidence, severity, or duration of symptoms, and is not limited to absence of symptoms or elimination of symptoms. Thus, treatment includes any decrease in incidence, duration, intensity, frequency, etc. of adverse gastrointestinal symptoms including, but not limited to, headache, nausea, vomiting, diarrhea, constipation, cramping, bloating, and combinations thereof. The formulations may reduce symptoms at any time during tranexamic acid therapy, but minimized adverse effects are particularly noted immediately or shortly after dosing, that is, within the first few hours after dosing. As used herein, adverse gastrointestinal effects and side effects are used interchangeably to indicate nontherapeutic effects (i.e., not relating to any possible beneficial effects due to tranexamic acid), ranging from unpleasant but tolerable sensations to severe gastrointestinal symptoms. As used herein, the terms oral formulations, ingestible formulations, and orally administered formulations are used interchangeably and include any dosage forms which are ingested by mouth, including, but not limited to, tablets, pills, liquids, gelcaps, softgels, dragees, capsules, powders, granules, pellets, etc.

Modified release formulations of tranexamic acid include tablets, pellets, granules, capsules, or other oral dosage forms prepared in such a way to release tranexamic acid in a designed manner. In certain embodiments, the modified release material is a gel-forming polymer, a hydratable polymer, a water soluble polymer, a water swellable polymer, or mixtures thereof.

In certain embodiments, modified release tranexamic acid tablets are prepared by adding a modified release material comprising a gel-forming or hydratable polymer to a tranexamic tablet composition. Suitable gel-forming or hydratable polymers include, but are not limited to, hydroxypropylcellulose, hydroxypropylmethylcellulose or hypromellose, carboxymethylcellulose, polyvinyl alcohol, etc. This provides a compressed tablet that may or may not be film coated. The tablet releases tranexamic acid by diffusion of tranexamic acid through the tablet matrix, or by erosion of the tablet matrix, or by a combination of diffusion from and erosion of the tablet matrix. Tablets formed with water swellable polymers release tranexamic acid by diffusion of tranexamic acid through the tablet matrix, or by erosion of the tablet matrix, or by a combination of diffusion from and erosion of the tablet matrix. One or more water-soluble hydrophilic polymer(s) may also be used. These include polyvinylpyrrolidine, hydroxypropyl cellulose, hydroxypropylmethylcellulose, now referred to as hypromellose (e.g., Methocel™, Dow Chemical Company), methyl cellulose, vinyl acetate/crotonic acid copolymers, methacrylic acid copolymers, maleic anhydride/methyl vinyl ether copolymers, derivatives thereof and mixtures thereof. In various embodiments, the polymer is hydroxypropyl cellulose or hydroxypropylmethylcellulose. The polymer may be hydroxypropyl-methyl cellulose with a viscosity ranging from about 50 cps to about 200 cps. The polymer may be hydroxypropyl-methyl cellulose with a viscosity of 100 cps, commercially available as Methocel™ K 100 LV (Dow Chemical Company). The amount of polymer in the composition may be in the range of about 5% by weight to about 50% by weight of the composition. In various embodiments, the polymer is in the range of about 10% by weight to about 35% by weight of the composition, or about 10% by weight to about 30% by weight of the composition.

In certain embodiments the modified release material comprises a vinyl polymer, phthalic acid derivative of vinyl copolymer, hydroxyalkylcellulose, alkylcellulose (e.g., ethylcellulose), cellulose acetate, hydroxyalkylcellulose acetate, cellulose ether, alkylcellulose acetate and partial esters thereof, and polymers and copolymers of lower alkyl acrylic acids and lower alkyl acrylates and partial esters thereof, or combination thereof. In preferred embodiments the modified release material comprises hydroxypropylcellulose, hydryoxpropylmethylcellulose, carboxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, methylcellulose, vinyl acetate/crotonic acid copolymers, methacrylic acid copolymers, maleic anhydride/methyl vinyl ether copolymers, derivatives thereof, and mixtures thereof. In further preferred embodiments the modified release material comprises a polymer such as a methacrylic acid copolymer. These are copolymers of methacrylic acid with neutral acrylate or methacrylate esters such as ethyl acrylate or methyl methacrylate.

In certain embodiments the modified release material comprises a pH independent binder or film-forming agent such as hydroxypropyl methylcellulose, hydroxypropyl cellulose, methylcellulose, polyvinylpyrrolidone, neutral poly(meth)acrylate esters (e.g., the methyl methacrylate/ethyl acrylate copolymers sold as Eudragit® (Rohm Pharma), starches, gelatin, sugars such as glucose, sucrose, and mannitol, silicic acid, carboxymethylcellulose, and the like, diluents such as lactose, mannitol, dry starch, microcrystalline cellulose and the like, surface active agents such as polyoxyethylene sorbitan esters, sorbitan ethers, and the like, coloring agents, flavoring agents, lubricants such as talc, calcium stearate, and magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and other tableting aids. Any combination of the aforementioned binders or film-forming agents may be included in the modified release material. The modified release material may be combined with tranexamic acid to form modified release dosage forms.

In certain embodiments, the formulation includes tranexamic acid in the range of about 50% by weight to about 95% or more by weight of the formulation. In other embodiments, tranexamic acid is in the range of about 60% by weight to about 90% by weight, or about 60% by weight to about 80% by weight of the formulation. The remaining weight may be made up of the modified release material and additional excipients.

To prepare modified release tablet formulations, the agent or modified release material to slow the release of tranexamic acid may be incorporated into the tablet matrix or coated onto the tablet surface or both. In certain embodiments, tablet formulations prepared are formulated by granulating a blend of powders of the modified release material. The powder blend is formed by combining portions of the powdered components that make up the tablet. These powders are intimately mixed by dry-blending. The dry blended mixture is granulated by wet mixing of a solution of a binding agent with the powder blend. The time for such wet mixing may be controlled to influence the dissolution rate of the formulation. For example, the total powder mix time, that is, the time during which the powder is granulated, may range from about 1 min to about 10 min, or from about 2 min to about 5 min. Following granulation, the particles are removed from the granulator and placed in a fluid bed dryer, a vacuum dryer, a microwave dryer, or a tray dryer for drying. Drying conditions are sufficient to remove unwanted granulating solvent, typically water, or to reduce the amount of granulating solvent to an acceptable level. Drying conditions in a fluid bed dryer or tray dryer are typically about 50 to 70° C. The granulate is dried, screened, mixed with additional excipients such as disintegrating agents, flow agents, or compression aids and lubricants such as talc, stearic acid, or magnesium stearate, and compressed into tablets.

In certain embodiments, the tablet that contains a modified release material within the tablet matrix may be coated with an optional film-forming agent. This applied film may aid in identification, mask an unpleasant taste, allow desired colors and surface appearance, provide enhanced elegance, aid in swallowing, aid in enteric coating, etc. The amount of film-forming agent may be in the range of about 2% tablet weight to about 4% tablet weight. Suitable film-forming agents are known to one skilled in the art and include hydroxypropyl cellulose, cellulose ester, cellulose ether, one or more acrylic polymer(s), hydroxypropyl methylcellulose, cationic methacrylate copolymers (diethylaminoethyl)methacrylate/methyl-butyl-methacrylate copolymers such as Eudragit E® (Rohm Pharma) and the like. The film-forming agents may optionally contain colorants, plasticizers, fillers, etc. including, but not limited to, propylene glycol, sorbitan monooleate, sorbic acid, titanium dioxide, and one or more pharmaceutically acceptable dye(s).

In certain embodiments, the tranexamic acid tablets of the invention are coated with a modified release material. In certain embodiments, tranexamic acid tablets are formulated by dry blending, rotary compacting, or wet granulating powders composed of tranexamic acid and tablet excipients. These powders are compressed into an immediate release tablet. Coating this immediate release tablet with a modified release material as described herein renders this tranexamic acid tablet as a modified release tablet.

In addition to the modified release material, the formulations of the invention may also contain suitable quantities of other materials, e.g. preservatives, diluents (e.g., microcrystalline cellulose), lubricants (e.g., stearic acid, magnesium stearate, and the like), binders (e.g., povidone, starch, and the like), disintegrants (e.g., croscarmellose sodium, corn starch, and the like), glidants (e.g., talc, colloidal silicon dioxide, and the like), granulating aids, colorants, and flavorants that are conventional in the pharmaceutical art. Specific examples of pharmaceutically acceptable excipients that may be used to formulate oral dosage forms are described in the Handbook of Pharmaceutical Excipients, American Pharmaceutical Association (2003), incorporated by reference herein.

The release process may be adjusted by varying the type, amount, and the ratio of the ingredients to produce the desired dissolution profile, as known to one skilled in the art. A coating may be a partially neutralized pH-dependent binder that controls the rate of tranexamic acid dissolution in aqueous media across the range of pH in the stomach, which has a pH of about 2, and the intestine, which has a pH of about 5.5 in its upper region. In certain embodiments, one or more pH dependent binders may be used to modify the dissolution profile so that tranexamic acid is released slowly and continuously as the formulation passes through the stomach and/or intestines.

In one embodiment, compressed modified release tablets are formulated to comply with USP criteria and to be of such a size and shape to be easy to swallow. The size of the tablet will depend upon the dose of tranexamic acid that is needed to provide adequate therapy and the particular formulation and excipients that are selected to provide the physical properties necessary for tableting and for modified release. In various embodiments, a compressed modified release tablet contains from about 500 mg to about 1 gram of tranexamic acid, or from about 600 mg to about 750 mg of tranexamic acid. The daily dose of tranexamic acid may be achieved by taking one or two tablets at each dosing time.

In certain embodiments, the tranexamic acid included in the dosage form is from about 375 mg to about 1500 mg, preferably from about 375 mg to about 1000 mg. In one embodiment, the dose of tranexamic acid per tablet is in the range of about 500 mg to about 1000 mg for tablets and from about 500 mg to about 1500 mg for a sachet filled with granules. In another embodiment, the dose of tranexamic acid is in the range of about 3 grams/day to about 6 grams/day in three or four divided doses. As an example, a total daily dose of 3 grams tranexamic acid may be divided into three doses of one tablet each with each tablet containing 1 gram tranexamic acid, or may be divided into four doses of one tablet each with each tablet containing 0.75 gram tranexamic acid. As another example, a total daily dose of 4 gram tranexamic acid may be divided into three doses of two tablets at each dose with each tablet containing 0.666 gram tranexamic acid, or may be divided into four doses of one tablet each with each tablet containing 1 gram tranexamic acid. As another example, a total daily dose of 5 gram tranexamic acid may be divided into three doses of one tablet each with each tablet containing 1.66 gram tranexamic acid, or may be divided into four doses of two tablets each with each tablet containing 0.625 gram tranexamic acid. As another example, a total daily dose of 6 gram tranexamic acid may be divided into three doses of two tablets each with each tablet containing 1 gram tranexamic acid, or may be divided into four doses of two tablets each with each tablet containing 0.75 gram tranexamic acid. For ease of swallowing, the dose of tranexamic acid taken at each dosing time may be delivered by taking multiple tablets. For example, the 4 gram daily dose may be delivered by taking two 666.67 mg tablets three times a day or two 500 mg tablets four times a day. Similarly, the 3 gram daily dose may be achieved by taking two 550 mg tablets three times a day or two 375 mg tablets four times a day. Alternatively, for ease of reference, a dose of 600 mg, 650 mg, or 700 mg of tranexamic acid per tablet may be used. In a preferred embodiment, a total daily dose of 3900 mg/day is administered in three divided doses of 1300 mg of two tablets at each dose with each tablet containing 650 mg of tranexamic acid. Alternatively, each dose may be delivered by taking granules containing the prescribed amount of tranexamic acid presented in a convenient unit dose package. Such examples are not limiting and other doses within these ranges will be appreciated by those skilled in the art.

Alternatively, modified release tranexamic acid formulations may be administered by pellets or granules in e.g., a sachet or capsule. Modified release tranexamic acid pellets or granules may be prepared by using materials to modify the release of tranexamic acid from the granule or pellet matrix. Modified release preparations may also be formulated using coatings to modify the release of tranexamic acid from the granule or pellet. U.S. Pat. Nos. 5,650,174; and 5,229,135 each of which is expressly incorporated by reference herein in its entirety, disclose variations on fabricating a pellet or nonpareil dosage form. Spheres are filled into packets, termed sachets, or capsules which are filled by weight to contain the prescribed dose of drug. Multiparticulates may be coated with an modified release coating, as disclosed in U.S. Pat. No. 6,066,339, which is expressly incorporated by reference herein its entirety. Coated multiparticulates may be packaged in capsules or sachets. The formulation of granules or pellets for modified release is described in Multiparticulate Oral Drug Delivery, Ghebre-Sellassie, Ed. in Drugs and the Pharmaceutical Sciences, Vol. 65 Marcel Dekker Inc. NY, 1994 and in the relevant parts of the references for modified release formulations previously cited and the relevant portions incorporated herein by reference.

In certain embodiments, the inventive tranexamic acid formulations may be used for additional indications other than menorrhagia, such as conization of the cervix, epistaxis, hyphema, hereditary angioneurotic edema, a patient with a blood coagulation disorder undergoing dental surgery, combinations thereof, and the like.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The invention will be further appreciated with respect to the following non-limiting examples. Other variations or embodiments of the invention will also be apparent to one of ordinary skill in the art from the above descriptions and examples. Thus, the forgoing embodiments are not to be construed as limiting the scope of this invention.

Example 1

Modified release 650 mg tranexamic acid tablets were prepared having the ingredients listed in the Table 1 below:

TABLE 1 Quantity Quantity per batch per tablet Ingredient (kg) (mg) Active Ingredient Tranexamic Acid, EP 84.50 650.0 Inactive Ingredients Microcrystalline Cellulose NF (Avicel PH 101) 5.753 44.25 Colloidal Silicon Dioxide NF 0.0975 0.75 Pregelatinized Corn Starch, NF 6.435 49.50 Hypromellose, USP (Methocel K3 Premium LV) 19.110 147.00 Povidone, USP (K value range 29-32) 4.680 36.00 Stearic Acid, NF (powder) 2.340 18.00 Magnesium Stearate, NF (powder) 0.585 4.50 Purified Water USP* 17.550 135.00 *Purified water is removed during processing The formulation of Example 1 was prepared as follows: 1. Weigh all ingredients and keep in moisture resistant containers until ready for use. 2. Measure water into a container. Mix povidone at medium speed until completely dissolved. 3. Add tranexamic acid, microcrystalline cellulose (MCC), pregelatinized corn starch, and colloidal silicon dioxide to the high shear mixer. 4. Mix using impeller only. 5. Mix for an additional time (impeller only). Add all of the povidone solution during this mixing step. 6. Mix until adequately granulated (impeller and chopper). Proceed only when desired granulation has been achieved. Add additional water if necessary. 7. Dry the granulation to moisture content of NMT 1.2%. 8. Pass the granulation through the oscillating granulator equipped with a #30 mesh screen. Weigh the granulation. Add granulation to the V-Blender. 9. Add the hypromellose USP Methocel K3 Premium to the V-blender. Blend. 10. Pass magnesium stearate and stearic acid through oscillating granulator equipped with a #40 mesh screen. Add magnesium stearate and stearic acid to the V-blender and blend. 11. Perform specified physical property testing. Proceed to compression. 12. Compress tablets to desired weight.

Example 2

In Example 2, immediate release 650 mg tranexamic acid tablets were prepared having the ingredients listed in Table 2 below:

TABLE 2 Quantity Quantity per Ingredient per batch (kg) tablet (mg) Active Ingredient Tranexamic Acid, EP (650 mg/tab) 84.50 650.0 Inactive Ingredients Microcrystalline Cellulose, NF 5.753 44.25 (Avicel PH 101) Microcrystalline Cellulose, NF 10.660 82.00 (Avicel PH 102) Colloidal Silicon Dioxide, NF 0.0975 0.75 Pregelatinized Corn Starch, NF 6.435 49.50 Croscarmellose Sodium, NF 19.50 15.00 Povidone, USP (K value range 29-32) 4.680 36.00 Stearic Acid, NF (powder) 2.340 18.00 Magnesium Stearate, NF (powder) 0.585 4.50 Purified Water, USP* 17.550 135.00 Film Coating (Inactive Ingredients)** Opadry White YS-1-7003 4.110 — Purified Water, USP 36.990 — *Purified water is removed during processing **6 kg excess prepared to account for losses during transfer The formulation of Example 2 was prepared as follows: 1. Weigh all ingredients and keep in moisture resistant containers until ready for use. 2. Measure water into a container. Mix povidone at medium speed until completely dissolved. 3. Add tranexamic acid, microcrystalline cellulose (MCC), pregelatinized corn starch, and colloidal silicon dioxide to the high shear mixer. 4. Mix using impeller only. 5. Mix for an additional time (impeller only). Add all of the povidone solution during this mixing step. 6. Mix until adequately granulated (impeller and chopper). Proceed only when desired granulation has been achieved. Add additional water if necessary. 7. Dry the granulation to moisture content of NMT 1.2%. 8. Pass the granulation through the oscillating granulator equipped with a #30 mesh screen. Weigh the granulation. Add granulation to the V-Blender. 9. Add the croscarmellose sodium and MCC to the V-Blender and blend. 10. Pass magnesium stearate and stearic acid through oscillating granulator equipped with a #40 mesh screen. Add magnesium stearate and stearic acid to the V-blender and blend. 11. Perform specified physical property testing. Proceed to compression. 12. Compress tablets. 12. After compression, spray coat the compressed dosage forms with the Opadry White in water.

Example 3

In Example 3, modified release 650 mg tranexamic acid tablets were prepared as in Example 1 and coated with a film coating similar to the immediate release tablets of Example 2. The ingredients are listed in Table 3 below:

TABLE 3 Quantity Quantity per batch per tablet Ingredient (kg) (mg) Active Ingredient Tranexamic Acid, EP 84.50 650.0 Inactive Ingredients Microcrystalline Cellulose NF (Avicel PH 101) 5.753 44.25 Colloidal Silicon Dioxide NF 0.0975 0.75 Pregelatinized Corn Starch, NF 6.435 49.50 Hypromellose, USP (Methocel K3 Premium LV) 19.110 147.00 Povidone, USP (K value range 29-32) 4.680 36.00 Stearic Acid, NF (powder) 2.340 18.00 Magnesium Stearate, NF (powder) 0.585 4.50 Purified Water USP* 17.550 135.00 Film Coating (Inactive Ingredients)** Opadry White YS-1-7003 4.305 — Purified Water, USP 38.750 — *Purified water is removed during processing **6 kg excess prepared to account for losses during transfer

Example 4 Bioavailability and Bioequivalence Evaluation

In Example 4, a comparative, randomized, single dose, 4-way Crossover Absolute Bioavailability (BA) and Bioequivalence (BE) study of Tranexamic Acid Tablet Formulations prepared in accordance with Examples 1 and 2 in Healthy Adult Women Volunteers under Fasting Conditions was performed. The objective was to assess the bioequivalence of a 650 mg modified release tablet formulation prepared in accordance with Example 1 compared to the immediate release reference tablet formulation of tranexamic acid prepared in accordance with Example 2, and to determine the bioavailability of the modified tablet formulation to the approved IV (1 g) formulation Cyklokapron® by Pharmacia & Upjohn. The design was a randomized, 4-way crossover, comparative BE and BA determination. All oral doses administered were 1.3 g. Twenty-eight (28) healthy non-smoking adult female volunteer subjects were enrolled in the study. Sample size was calculated assuming a 25% CV in AUC_(inf). The study endpoints were the 90% confidence intervals of the ratio of least-squares means of the pharmacokinetic parameters AUC_(0-t), AUC_(inf) and C_(max) of the modified release formulation to the immediate-release formulation from serum concentration-time data drawn up to 36 hours after a single dose of drug. In addition, the bioavailability of the tablet formulations were calculated. Smokers, oral contraceptive users, those with a previous history of thromboembolic events and altered vision were excluded from the study. ECG monitoring was performed before, during and after the estimated times of peak serum tranexamic acid concentrations exposure. Adverse events were captured and recorded throughout the trial period.

In the study, subjects were randomized to receive single oral 1.3 g (2×650 mg tablets) dose of tranexamic acid in tablet forms which included a modified release dosage form and an immediate release dosage form. Subjects were also administered a single 1 g (10 ml) IV solution of tranexamic acid (100 mg/ml concentration).

A summary of the pharmacokinetic results from the study of Example 4 are listed in the tables below.

TABLE 4 Summary of Results - Tranexamic Acid in Plasma Pharmacokinetic Parameters (N = 26) ln AUC 0-t* ln AUCinf* ln Cmax* (mcg · h/mL) (mcg · h/mL) (mcg/mL) Modified Release formulation Mean 66.703 69.642 11.251088 CV 26.8 27.2 29.1 N 26 24 26 Immediate Release formulation Mean 70.157 72.656 12.260414 CV 16.2 16.4 23.0 N 26 24 26 Least-Squares Mean: Modified Release 66.935 68.891 11.321919 Immediate Release 70.051 72.411 12.258222 Ratio of 95.6 95.1 92.4 Least-Squares Mean (modified release/immediate release)% *For In-transformed parameters, the antilog of the mean (i.e. the geometric mean) is reported. AUCinf, kel, half-life and F could not be estimated for some subjects. AUG 0-t is the area under the plasma concentration versus time curve, from time 0 to the last measurable concentration, as calculated by the linear trapezoidal method.

TABLE 5 Summary of Results - Tranexamic Acid in Plasma Pharmacokinetic Parameters (N = 26) Tmax Half-life kel F (h) (h) (1/h) (%) Modified Release formulation Mean 2.942 11.370 0.06300 44.93 CV 22.7 17.6 19.4 25.3 n 26 26 26 24 Immediate Release formulation Mean 2.808 11.013 0.06438 46.04 CV 20.8 15.5 15.3 16.1 n 26 24 24 24

TABLE 6 Summary of Results - Tranexamic Acid in Plasma Pharmacokinetic Parameters (N = 26) Ln AUC 0-t* ln AUCinf* ln Cmax* (mcg · h/mL) (mcg · h/mL) (mcg/mL) 90% Confidence Intervals (Modified release/Immediate release) % lower limit: 87.8% 87.4% 84.0% upper limit: 104.0% 103.5% 101.6% p-Value (ANOVA) Modified vs Immediate 0.3721 0.3259 0.1676 Period 0.0704 0.0499 0.0356 Sequence 0.7734 0.7978 0.8207 Intrasubject CV % 18.3 17.4 20.6 *For In-transformed parameters, the antilog of the mean (i.e. the geometric mean) is reported. AUCinf, kel, half-life and F could not be estimated for some subjects.

Concentration-time profiles for the study of Example 4 are presented on semi-log and linear scale over 36 hours and are depicted in FIGS. 3 and 4.

The following pharmacokinetic parameters in the table below were calculated for tranexamic acid in plasma for the study of Example 4.

-   -   MRT: The mean residence time (MRT) after intravenous         administration of tranexamic acid was determined using the         equation,         AUMC/AUC+infusion time/2,     -    where the AUMC is the area under the moment-time curve.     -   MTT: Following oral administration of the Modified Release and         Immediate Release formulations, the mean transit time (MTT) of         tranexamic acid was calculated by dividing the AUMC by the AUC.     -   MAT: The mean absorption time (MAT) for the two formulations was         derived by subtracting the MRT from the MTT.         Mean (±SD) results are presented in the table below:

TABLE 7 IV Modified Release Immediate Release MRT (hours) 3.51 ± 0.38 N/A N/A MTT (hours) N/A 7.70 ± 0.72 7.21 ± 1.01 MAT (hours) N/A 4.18 ± 0.70 3.70 ± 0.94

The mean transit time (MTT) and mean absorption time (MAT) of the Modified Release formulation of tranexamic acid was approximately 30 minutes longer than that observed for the Immediate Release formulation.

The most frequently reported adverse events from the study of Example 4 are listed in the table below. The table lists the number of subjects reporting adverse events, and the percentage of subjects is in parentheses.

TABLE 8 Treatment Modified Immediate IV solution Release Release (10 × (2 × 650 mg) (2 × 650 mg) 100 mg/ml) Adverse Events (n = 27) (n = 27) (n = 27) Headache  4 (15%)  7 (26%)  7 (26%) Nausea 0 (0%) 2 (7%) 10 (37%) Dizziness 0 (0%) 0 (0%) 11 (41%) Feeling Hot 0 (0%) 0 (0%)  6 (22%) Nasal Congestion 2 (7%) 1 (4%) 1 (4%) Cough 0 (0%) 0 (0%) 2 (7%) Urine odor abnormal 2 (7%) 0 (0%) 1 (4%)

Dissolution Results for Immediate Release and Modified Release Formulations prepared in accordance with Examples 2 and 1 respectively used in the study of Example 4 tested under USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. are listed in the tables below.

TABLE 9 Test Results for the Immediate Release Formulation in Table 2. % RSD Assay 99.9% Content Uniformity 99.4%   0.7% Unknown Related NMT 0.2% Each <0.1% Substance Total Related Substances NMT 2.0% Total <0.1% and Impurities Dissolution Profile 15 min. 58.0% 30 min. 96.0% 45 min. 102.0%  60 min. 104.0% 

TABLE 10 Test Results for the Modified Release Formulation in Table 1 % RSD Assay 99.4% Content Uniformity 98.5%   0.6% Unknown Related NMT 0.2% Each <0.1% Substance Total Related Substances NMT 2.0% Total <0.1% and Impurities Dissolution Profile 15 min. 21.0% 30 min. 40.0% 45 min. 58.0% 60 min. 73.0% 90 min. 98.0%

Conclusions

The ratios of least-squares means and the 90% confidence intervals derived from the analyses of the ln-transformed pharmacokinetic parameters AUC_(0-t), AUC_(inf) and C_(max) for tranexamic acid in plasma were within the 80-125% Food and Drug Administration (FDA) acceptance range for the modified release formulation versus the immediate release formulation under fasting conditions.

The absolute bioavailability of the modified release and immediate release tablet formulations were 44.93% and 46.04% respectively.

Based on these results, the modified release tranexamic acid tablet formulation and the immediate release tranexamic acid formulation are bioequivalent under fasting conditions.

Example 4A Comparative Example

Comparative Example 4A, a 500 mg immediate release tranexamic acid tablet, approved and marketed in Canada under the name Cyklokapron was obtained and dissolution tested under USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C. The dissolution results are listed in Table 10A below:

TABLE 10A % dissolved % dissolved % dissolve % dissolved Sample # in 15 min. in 30 min. in 45 min. in 60 min. 1 102 104 105 106 2 102 104 105 106 3 101 102 102 105 4 99 101 102 103 5 100 102 103 104 6 99 101 102 104 Average 101 102 103 105 % RSD 1.4 1.3 1.4 1.1

Example 5

In Example 5, based on single dose pharmacokinetic parameters, pharmacokinetic simulations of serum concentrations were performed to compare dosing the modified release formulation of Example 4 at every 8 hours (Q8H: at 6:00 AM, 2:00 PM, 10:00 PM) and dosing three times a day, other than every 8 hours (TID: at 8:00 AM, 2:00 PM, and 10:00 PM). The results are provided in Tables 11-14 below.

TABLE 11 Tranexamic Acid - Modified Release Formulation Dosage Regimen Simulation - ORAL 1.3 g q8hr Time (h) Dose(mcg) Conc.(mcg/mL) 0 1.30E+06 0 1 0 4.0594 2 0 10.0551 3 0 10.6433 4 0 9.20306 5 0 7.26932 6 0 5.4699 8 1.30E+06 2.89909 9 0 6.15391 10 0 11.5813 11 0 11.7752 12 0 10.0646 13 0 7.94622 14 0 6.02067 15 0 4.4712 16 1.30E+06 3.30248 17 0 6.51406 18 0 11.9097 19 0 12.0794 20 0 10.3495 21 0 8.21523 22 0 6.2761 23 0 4.71463 24 1.30E+06 3.53505 25 0 6.73663 26 0 12.1229 27 0 12.2838 28 0 10.5455 29 0 8.40336 30 0 6.45664 31 0 4.88791 32 1.30E+06 3.70138 33 0 6.89628 34 0 12.2762 35 0 12.4309 36 0 10.6868 37 0 8.53894 38 0 6.5868 39 0 5.01286 40 1.30E+06 3.82133 41 0 7.01144 42 0 12.3867 43 0 12.537 44 0 10.7887 45 0 8.63675 46 0 6.68069 47 0 5.103 48 1.30E+06 3.90786 49 0 7.09451 50 0 12.4665 51 0 12.6136 52 0 10.8621 53 0 8.70731 54 0 6.74842 55 0 5.16802 56 1.30E+06 3.97028 57 0 7.15443 58 0 12.524 59 0 12.6688 60 0 10.9152 61 0 8.7582 62 0 6.79728 63 0 5.21493 64 1.30E+06 4.01531 65 0 7.19766 66 0 12.5655 67 0 12.7087 68 0 10.9534 69 0 8.79492 70 0 6.83253 71 0 5.24877 72 1.30E+06 4.0478 73 0 7.22885 74 0 12.5954 75 0 12.7374 76 0 10.981 77 0 8.82141 78 0 6.85796 79 0 5.27318 80 1.30E+06 4.07124 81 0 7.25135 82 0 12.617 83 0 12.7581 84 0 11.0009 85 0 8.84052 86 0 6.87631 87 0 5.29079 88 1.30E+06 4.08814 89 0 7.26758 90 0 12.6326 91 0 12.7731 92 0 11.0153 93 0 8.8543 94 0 6.88954 95 0 5.3035 96 1.30E+06 4.10034 97 0 7.27929 98 0 12.6439 99 0 12.7839 100 0 11.0256 101 0 8.86425 102 0 6.89909 103 0 5.31266 104 1.30E+06 4.10913 105 0 7.28773 106 0 12.652 107 0 12.7917 108 0 11.0331 109 0 8.87142 110 0 6.90597 111 0 5.31927 112 1.30E+06 4.11548 113 0 7.29382 114 0 12.6578 115 0 12.7973 116 0 11.0385 117 0 8.8766 118 0 6.91094 119 0 5.32404 120 0 4.12006

Concentration-time profiles are presented over 120 hours for the modified release formulation in Table 12 and are depicted in FIG. 1. A 1 g formulation administered q8 h is also depicted for comparison purposes.

TABLE 12 Cmax, Cmin and Cavg for 1.3 g q8 hr simulation Simulation at 120 hours Pharmacokinetic Parameter Concentration Cmax 12.8 mcg/mL  Cmin 4.1 mcg/mL Cavg 8.4 mcg/ml

TABLE 13 Tranexamic Acid - Modified Release Formulation Dosage Regimen Simulation - ORAL 1.3 g TID (8:00 AM, 2:00 PM, and 10:00 PM) Time (h) Dose(mcg) Conc. (mcg/mL) 0 1.30E+06 0 1 0 4.0594 2 0 10.0551 3 0 10.6433 4 0 9.20306 5 0 7.26932 6 1.30E+06 5.4699 8 0 12.9542 9 0 12.7378 10 0 10.7293 11 0 8.40129 12 1.30E+06 6.33141 13 0 8.74352 14 0 13.505 15 0 13.2018 16 0 11.1327 17 0 8.76144 18 0 6.65976 19 0 4.98823 20 0 3.73474 21 0 2.8275 22 0 2.18502 23 0 1.73555 24 1.30E+06 1.42243 25 0 5.26298 26 0 11.104 27 0 11.5807 28 0 10.058 29 0 8.06103 30 1.30E+06 6.21137 31 0 8.76659 32 0 13.6187 33 0 13.3709 34 0 11.334 35 0 8.97998 36 1.30E+06 6.88576 37 0 9.27495 38 0 14.0147 39 0 13.6908 40 0 11.6019 41 0 9.21185 42 0 7.09208 43 0 5.40321 44 0 4.1331 45 0 3.20991 46 0 2.55212 47 0 2.08796 48 1.30E+06 1.76074 49 0 5.58776 50 0 11.4158 51 0 11.88 52 0 10.3453 53 0 8.33688 54 1.30E+06 6.47618 55 0 9.02081 56 0 13.8627 57 0 13.6052 58 0 11.5589 59 0 9.1959 60 1.30E+06 7.09304 61 0 9.47395 62 0 14.2057 63 0 13.8742 64 0 11.778 65 0 9.38036 66 0 7.25433 67 0 5.55898 68 0 4.28264 69 0 3.35346 70 0 2.68993 71 0 2.22026 72 1.30E+06 1.88775 73 0 5.70968 74 0 11.5329 75 0 11.9924 76 0 10.4532 77 0 8.44044 78 1.30E+06 6.57559 79 0 9.11625 80 0 13.9543 81 0 13.6931 82 0 11.6434 83 0 9.27696 84 1.30E+06 7.17086 85 0 9.54865 86 0 14.2775 87 0 13.943 88 0 11.8441 89 0 9.44431 90 0 7.31525 91 0 5.61745 92 0 4.33877 93 0 3.40735 94 0 2.74167 95 0 2.26992 96 1.30E+06 1.93543 97 0 5.75546 98 0 11.5768 99 0 12.0346 100 0 10.4937 101 0 8.47931 102 1.30E+06 6.61292 103 0 9.15208 104 0 13.9887 105 0 13.7261 106 0 11.6751 107 0 9.30739 108 1.30E+06 7.20008 109 0 9.5767 110 0 14.3044 111 0 13.9689 112 0 11.8689 113 0 9.46813 114 0 7.33811 115 0 5.63941 116 0 4.35985 117 0 3.42759 118 0 2.76109 119 0 2.28857 120 0 1.95333

Concentration-time profiles are presented over 120 hours for the modified release formulation in Table 14 and are depicted in FIG. 2. A 1 g formulation administered TID is also depicted for comparison purposes.

TABLE 14 Cmax, Cmin and Cavg for 1.3 g TID (8:00 AM, 2:00 PM, and 10:00 PM) Simulation at 120 hours Pharmacokinetic Parameter Conc. Cmax 12.0, 14.0, 14.3 mcg/mL Cmin 1.9, 6.6, 7.2 mcg/mL Cavg 8.4 mcg/mL

Example 6

In Example 6, a study of a single dose followed by multiple doses, was performed on 20 healthy non-smoking adult female volunteers using a modified release formulation prepared in accordance with Example 1. After an overnight fast, subjects received a single oral dose of tranexamic acid (1.3 g) on Day 1. Blood samples were taken before dosing and up to 36 hours post-dose. Subjects received another single oral dose of tranexamic acid (1.3 g) on the evening of Day 2, and 3 times a day (every 8 hours) starting on the morning of Day 3 until the last dose on the morning of Day 7. Blood samples were taken before the 6th, 9th, 12th and 15th dose (the last dose) for the determination of C_(min), and up to 8 hours after the last dose, for the determination of drug concentration at steady-state. Subjects were housed from at least 10 hours before the 1st dose on Day 1 until after the 8-hour blood draw following the 15th dose (on Day 7).

Tranexamic acid is minimally bound (approximately 3%) to plasma proteins (mainly plasminogen) at “typical” therapeutic plasma concentrations of approximately 5-15 mg/L. The main route of elimination of tranexamic acid is renal glomerular filtration. After oral administration of tranexamic acid (250 or 500 mg) to healthy adults, between 40-70% of the administered dose is excreted unchanged in the urine within 24 hours. After IV administration (1 g) 30% of the dose is excreted unchanged in the urine within one hour, 45-55% within 2-3 hours and 90% within 24 hours.

The beta elimination half-life of tranexamic acid is 2 hours. Based on published data, the mean C_(max) and AUC₀₋₆ pharmacokinetic parameters after a single 1.3 g oral dose of tranexamic acid are expected to be approximately 65% of those achieved with a 2 g dose (i.e. ˜10 mg/L and ˜40 mg-h/L, C_(max) and AUC₀₋₆ under fasting conditions, respectively).

However, the pharmacokinetics of tranexamic acid were not adequately characterized in Pilbrant, et al., Eur. J. Clin. Pharmacol, (1981)-20:65-72, since blood samples were collected for up to only 6 hours post-dose. In addition, the plasma concentration-time curves after IV administration showed three exponential phases, with a gamma elimination half-life of approximately 7 hours. For this reason, the concentration-time profile of tranexamic acid was estimated by simulating the data over 36 hours, after oral administration of a 1.3 g dose under fasting conditions, using NONMEM. Based on the simulation results, it would be appropriate to collect blood samples until 36 hours in order to characterize the AUC, Cmax, tmax, t½ and F.

The objective of this study of Example 6 was to assess the pharmacokinetic linearity of the test tablet formulation of tranexamic acid (modified release), after a single oral dose (Day 1) compared to a daily (1.3 g every 8 hours) dosage regimen (Days 2 to 7), under fasting conditions.

In the study of Example 6, blood samples (1×5 mL) were collected in blood collection tubes containing lithium heparin at Hour 0 (pre-dose) on Day 1, and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 14, 24, 28, 32, and 36 hours post-dose. Blood samples for Cmin determinations were also collected immediately before the 6th, 9th, 12th, and 15th doses on Days 4, 5, 6, and 7, respectively, and at the following times after the 15th dose: 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, and 8 hours. Plasma samples were separated by centrifugation, then frozen at −20° C.±10° C. and kept frozen until assayed at AAI Development Services in New-Ulm, Germany.

Noncompartmental Pharmacokinetic Parameters

Calculations for plasma tranexamic acid were calculated by noncompartmental methods using the following pharmacokinetic parameters in Tables 15 and 16:

Day 1:

TABLE 15 AUC 0-t: The area under the plasma concentration versus time curve, from time 0 to the last measurable concentration, as calculated by the linear trapezoidal method. AUCinf: The area under the plasma concentration versus time curve from time 0 to infinity. AUCinf was calculated as the sum of AUC 0-t plus the ratio of the last measurable plasma concentration to the elimination rate constant. AUC/AUCinf: The ratio of AUC 0-t to AUCinf. Cmax: Maximum measured plasma concentration over the time span specified. tmax: Time of the maximum measured plasma concentration. If the maximum value occured at more than one time point, tmax was defined as the first time point with this value. kel: Apparent first-order terminal elimination rate constant calculated from a semi-log plot of the plasma concentration versus time curve. This parameter was calculated by linear least squares regression analysis using the maximum number of points in the terminal log- linear phase (e.g. three or more non-zero plasma concentrations). t½: The apparent first-order terminal elimination half-life was calculated as 0.693/kel.

No value for kel, AUCinf or t½ were reported for cases that did not exhibit a terminal log-linear phase in the concentration versus time profile.

Day 7:

TABLE 16 AUCτ: The area under the plasma concentration versus time curve over the final dosing interval, as calculated by the linear trapezoid method. Cmax: Maximum measured plasma concentration over the final dosing interval. Cmin: Measured plasma concentration prior to the morning dose. tmax: Time of the maximum measured plasma concentration over the final dosing interval. If the maximum value occured at more than one time point, tmax was defined as the first time point with this value. Flux: Percent fluctuation was calculated as follows: Flux 1: $\frac{{Cmax} - {Cmin}}{Cssav} \times 100$ where Cssav was calculated as the ratio of AUC 0-τ to the dosing interval, τ Flux 2: $\frac{{Cmax} - {Cmin}}{Cmin} \times 100$ Compartmental Pharmacokinetic Parameters

Compartmental analysis was performed on tranexamic acid data following single and multiple oral administrations of the modified release (MR) tablet formulation. Multiple compartmental models were constructed and their ability to fit plasma concentrations of tranexamic acid were evaluated using a standard two-stage (STS) approach with ADAPT-II (maximum likelihood analysis). The discrimination process was performed by computing the Akaike Information Criterion Test (AIC), the minimum value of the objective function (OBJ) and by looking at pertinent graphical representations of goodness of fit (e.g. fitted and observed concentrations versus time).

The final analysis was performed using an iterative two-stage approach with the IT2S® software. This software uses a population methodology which allows one to provide robust PK parameter estimates on an individual subject and population basis. All relevant pharmacokinetic parameters were calculated and reported. Concentrations were modeled using a weighting procedure of W_(j)=1/S_(j) ² where the variance σ_(j) ² was calculated for each observation using the equation σj²=(a+b*Y_(j))² where a and b are the intercept and slope of each variance model. The slope is the residual variability associated with each concentration (includes the intra-individual variability and the sum of all experimental errors), and the intercept is related to the limit of detection of the analytical assay. All PK parameter estimates were updated iteratively during the population PK analysis (VARUP, IT2S®) until stable values were found. The analysis included the quantitative estimation of population PK parameters and interindividual variability of tranexamic acid in plasma.

Individual profiles of observed vs fitted plasma concentrations of tranexamic acid were provided for the MR formulation.

Statistical Analyses

Descriptive Statistics

Descriptive statistics including arithmetic means, standard deviations and coefficients of variation were calculated on the individual concentration and pharmacokinetic data. Additionally, geometric means were calculated for the parameters AUC_(0-t), AUC_(inf), and C_(max) for Day 1 and AUCτ, C_(max) and C_(min) for Day 7.

Time Dependence Pharmacokinetic Linearity

The pharmacokinetic parameter AUCτ (Day 7) was compared against AUC_(inf) (Day 1) using an analysis of variance (ANOVA) on the ln-transformed values for tranexamic acid. The ANOVA model included Group, Day (1 (AUC_(inf)) and 7 (AUCτ)) and the interaction Day*Group as fixed effects. All the interaction terms were not statistically significant, at a level of 5%, and were dropped from the final model. The ANOVA included calculation of least-squares means (LSM), the difference between Day LSM and the standard error associated with this difference. The above statistical analysis was done using the SAS® GLM procedure.

The ratio of LSM was calculated using the exponentiation of the Day LSM from the analysis on the ln-transformed response. The ratio was expressed as a percentage relative to AUC_(inf) (Day 1).

A ninety percent confidence interval for the ratio was derived by exponentiation of the confidence interval obtained for the difference between Day LSM resulting from the analysis on the ln-transformed response. The confidence interval was expressed as a percentage relative to AUC_(inf) (Day 1).

Steady-State Analysis

A steady-state analysis was performed, on the ln-transformed pre-dose Cmin concentrations at −72, −48, −24 and 0-hour time points, using Helmert's contrasts. The ANOVA model included Group, Time and the interaction Time*Group as fixed effects. In order to model the correlations within every subject, an appropriate variance-covariance matrix was chosen among the following: unstructured (UN), compound symmetry (CS), compound symmetry heterogeneous (CSH), variance component (VC), autoregressive (AR(1)), autoregressive heterogeneous (ARH(1)) and autoregressive moving average (ARMA(1,1)), using the Akaike's Burnham and Anderson criterion (AICC). All the interaction terms were not statistically significant, at a level of 5%, and were dropped from the final model. The ANOVA included also calculation of least-squares means (LSM) for each pre-dose C_(min) concentrations. Helmert's contrasts were constructed such that each time point is compared to the mean of subsequent time points. There are 3 contrasts associated to the 4 pre-dose concentration timepoints. They are listed in Table 17 below:

TABLE 17 Contrast Tests Compar. 1 Predose Day 4 compared to (mean predose of Day 5, 6 and 7) Compar. 2 Predose Day 5 compared to (mean predose of Day 6 and 7) Compar. 3 Predose Day 6 compared to predose Day 7 (0-hour)

The above statistical analyses were done using the SAS® Mixed procedure.

Formulae

The following formulae in Table 18 were used for the ratio of least-squares means and 90% confidence interval calculations derived from the ANOVA on the ln transformed pharmacokinetic parameters.

TABLE 18 Ratio of _(100 × e) (LSM_(Day 7) − LSM_(Day 1)) Least-squares Means: 90% Confidence _(100 × e) (LSM_(Day 7) − LSM_(Day 1) ± t_(df,0.05) × SE_(Day 7−Day 1)) Interval: Note: LSM_(Day 7) and LSM_(Day 1) are the least-squares means of Day 7 and Day 1, as computed by the LSMEANS statement of the SAS ® GLM procedure. t_(df,α) is the value of the Student's t distribution with df degrees of freedom (i.e. degrees of freedom for the error term from the analysis of variance) and a right-tail fractional area of α (α = 0.05). SE_(Day 7−Day 1) is the standard error of the difference between the adjusted Day means, as computed by the ESTIMATE statement in the SAS ® GLM procedure. Discussion of Pharmacokinetic Results Time Dependence Pharmacokinetic Linearity

The ANOVA model included Group, Day (1 (AUC_(inf)) and 7 (AUCτ)) and the interaction Day*Group as the fixed effect. All the interaction terms were not statistically significant, at a level of 5%, and were dropped from the final model. Pharmacokinetic linearity was calculated for the formulation using the same approach as above, but the ANOVA model included Group, Day 1 (AUCinf) and Day 7 (AUCτ)) and the interactions Group*Day as fixed effects and Subject nested within Group as a random effect.

The pharmacokinetic linearity results are summarized in the table below.

TABLE 19 90% Confidence Interval Formulation Ratio AUCτ/AUCinf Lower Limit Upper Limit MR 97.3 86.5 109.5

The pharmacokinetic linearity results indicate that the ratios of least-squares means of AUCτ(Day 7) to AUC_(inf) (Day 1) and the 90% confidence interval for the MR formulation were within the 80-125% acceptance range. Based on these results, the 650 mg tranexamic acid modified release tablets exhibited linear pharmacokinetics following repeated administration (7 days) of a 1.3 g dose under fasting conditions.

Steady-State Analysis

For the steady-state analysis, the CS variance-covariance matrix was chosen to model the correlations within every subject. Overall, the interaction term (i.e. Time*Group) was not statistically significant and was removed from the final ANOVA model. For each formulation, the same approach as above was used, but the ANOVA models included Group, Time and the interactions Time*Group as fixed effects.

A summary of LSM results for the steady-state analysis are summarized in Table 20A below.

TABLE 20A Times Formulation Days (hour) LSM derived from the ANOVA MR 4 −72 4.90536 5 −48 4.77323 6 −24 5.23678 7 0 5.15389

Summary of statistical comparisons for the steady-state analysis are summarized in Table 20B below

TABLE 20B Formulation Helmert's contrasts P-value MR Predose Day 4 compared to (mean predose of 0.4438 Day 5, 6 and 7) Predose Day 5 compared to (mean predose of 0.0393 Day 6 and 7) Predose Day 6 compared to predose Day 7 0.7318

Based on the results above, steady-state plasma concentration of tranexamic acid were reached on Day 4 (−72-hour), since the p value for the first contrast was not statistically significant at a 5% alpha error. It should be noted that the second comparison [Predose Day 5 compared to (mean of Day 6 and 7)] was found to be statistically significant.

The largest difference observed in predose plasma concentrations of tranexamic acid between the LSM of predose Day 5 compared to Day 6 and 7 was less than 10%, which is not considered clinically relevant. Moreover, the last contrast was not statistically significant and the observed difference between the LSM of predose Day 6 and 7 was less than 2%.

Compartmental Pharmacokinetic Analysis

The mean apparent oral clearance (CL/F) of the MR formulation calculated with compartmental methods was 17.7 L/h (295 mL/min). Based on previous data reported in the literature, the group of Pilbrant, et al., have determined that the urinary recovery of tranexamic acid exceeded 95% of the dose administered. Considering the bioavailability of the MR formulation (Mean F: 44.9%, See Table 5), the systemic clearance (CL) of tranexamic acid (295 mL/min×0.449=123 mL/min) would be close to the glomerular filtration rate in healthy subjects (125 mL/min)5.

Using compartmental methods, the mean T½γ for the MR formulation was 16.6 hours. Similar values of terminal elimination half-life were previously reported in the literature. Pilbrant A., et al., Eur. J. Clin. Pharmacol (1981), 20: 65-72.

Following a single oral dose of 1.3 g of the MR formulation, the mean plasma concentrations of tranexamic acid observed at 28, 32, and 36 hours were 0.19724, 0.15672, and 0.13624 mcg/mL, respectively. Considering the therapeutic window of tranexamic acid (5-15 mcg/mL) and the very low plasma concentration levels observed at these timepoints, the terminal elimination half-life (T½γ) characterizing the slow decline of plasma concentrations should not play a clinically significant role in the frequency of drug administration.

Pharmacokinetic Conclusions

The pharmacokinetic linearity results indicate that the ratios of least-squares means of AUCτ (Day 7) to AUCinf (Day 1) and the 90% confidence interval for the MR formulation were within the 80-125% acceptance range. Based on these results, the 650 mg tranexamic acid modified release tablets exhibited linear pharmacokinetics following repeated administration (7 days) of a 1.3 g dose under fasting conditions.

Steady-state plasma concentrations of tranexamic acid for the modified-release tablets were reached on Day 4 (−72-hour), since the p-value for the first contrast was not statistically significant at a 5% alpha error.

The pharmacokinetics of tranexamic acid was properly described using a three compartment PK model with linear elimination. The absorption kinetic of the single-dose (Day 1) data of tranexamic acid for the MR formulation was best described using a mixed-order rate constant of absorption.

Plasma Pharmacokinetic Parameters for the modified release (MR) formulation of Tranexamic Acid on day 1 are listed in Table 21 below.

TABLE 21 In AUC_(0-t)* In AUC_(inf)* In T_(max) Half-life (mcg · h/ml) (mcg · h/ml) C_(max)* (mcg/ml) (h) (h) K_(el) (1/h) Mean 74.571 76.875 13.176041 3.079 11.078 0.06443 CV % 31.3 30.4 33.1 25.0 16.9 18.3 N 19 19 19 19 19 19 *For In-transformed parameters, the antilog of the mean (i.e. the geometric mean) is reported; AUC_(0-t) = AUC post dose (0-36 hours)

Plasma Pharmacokinetic Parameters for the modified release (MR) formulation of Tranexamic Acid on day 7 are listed in Table 22 below.

TABLE 22 In In C_(max)* In C_(min)* T_(max) Flux 1** AUC_(τ)* (mcg · h/ml) (mcg/mL) (mcg/ml) (h) (%) Flux 2** (%) Mean 74.791 15.803509 5.157681 2.553 113.16 219.21 CV % 29.0 30.1 31.2 14.4 21.6 44.6 N 19 19 19 19 19 19 *For In-transformed parameters, the antilog of the mean (i.e. the geometric mean) is reported; AUC_(τ) = AUC dosing interval (8 hours) **Defined in Table 16

Conclusion

While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the spirit and scope of the present invention. Such modifications are understood to be within the scope of the appended claims. 

1. A method of treating menorrhagia, the method comprising: orally administering to a patient in need of such treatment a tranexamic acid formulation comprising: tranexamic acid or a pharmaceutically acceptable salt thereof; and a modified release material; wherein the tranexamic acid or pharmaceutically acceptable salt thereof is present in an amount from about 50% to about 95% by weight of the formulation; wherein the modified release material is present in an amount from about 5% to about 50% by weight of the formulation; wherein the formulation is administered as two oral dosage forms, each providing a dose of about 650 mg of tranexamic acid; and wherein said formulation provides an in-vitro dissolution release rate of the tranexamic acid or pharmaceutically acceptable salt thereof, when measured by a USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C., of less than about 40% by weight of the tranexamic acid or pharmaceutically acceptable salt thereof released at about 15 minutes, less than about 70% by weight of the tranexamic acid or pharmaceutically acceptable salt thereof released at about 45 minutes and not less than about 50% by weight of the tranexamic acid or pharmaceutically acceptable salt thereof released at about 90 minutes.
 2. The method of claim 1, wherein said formulation provides an in-vitro dissolution release rate of the tranexamic acid or pharmaceutically acceptable salt thereof, when measured by the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C., of about 0% to about 40% by weight of the tranexamic acid or pharmaceutically acceptable salt thereof released at about 15 minutes, from about 20% to about 60% by weight of the tranexamic acid or pharmaceutically acceptable salt thereof released at about 30 minutes, from about 40% to about 65% by weight of the tranexamic acid or pharmaceutically acceptable salt thereof released at about 45 minutes, from about 50% to about 95% by weight of the tranexamic acid or pharmaceutically acceptable salt thereof released at about 60 minutes, and not less than about 60% by weight of the tranexamic acid or pharmaceutically acceptable salt thereof released at about 90 minutes.
 3. The method of claim 1, wherein the formulation releases about 10% to about 25% by weight of the tranexamic acid or pharmaceutically acceptable salt thereof every 15 minutes when measured in vitro utilizing the USP 27 Apparatus Type II Paddle Method @ 50 RPM in 900 ml water at 37±0.5° C.
 4. The method of claim 1, wherein the formulation releases about 1% of the tranexamic acid or pharmaceutically acceptable salt thereof every minute when measured in-vitro utilizing the USP 27 Apparatus Type II paddle method at 50 RPM in 900 ml water at 37±0.5° C.
 5. The method of claim 1, wherein the tranexamic acid or pharmaceutically acceptable salt thereof is tranexamic acid.
 6. The method of claim 1, wherein a mean maximum plasma concentration (C_(max)) of tranexamic acid of from about 5 to about 17.5 mcg/ml is provided following the administration.
 7. The method of claim 1, wherein the formulation is in the form of a matrix tablet which comprises a drug mixed together with a granulated modified release material.
 8. The method of claim 1, wherein the tranexamic acid or pharmaceutically acceptable salt thereof is present in an amount from about 60% to about 90% by weight of the formulation.
 9. The method of claim 1, wherein the tranexamic acid or pharmaceutically acceptable salt thereof is present in an amount from about 60% to about 80% by weight of the formulation.
 10. The method of claim 1, wherein the modified release material is present in an amount from about 10% to about 35% by weight of the formulation.
 11. The method of claim 1, wherein: the tranexamic acid or pharmaceutically acceptable salt thereof is present in an amount from about 60% to about 90% by weight of the formulation; the modified release material is present in an amount from about 10% to about 35% by weight of the formulation; the formulation is in the form of a matrix tablet which comprises a granulated drug mixed together with the modified release material.
 12. The method of claim 11, wherein the tranexamic acid or pharmaceutically acceptable salt thereof is tranexamic acid. 